This invention relates to organic electroluminescent displays and organic electronic devices.
Pattern-wise thermal transfer of materials from donor sheets to receptor substrates has been proposed for a wide variety of applications. For example, materials can be selectively thermally transferred to form elements useful in electronic displays and other devices. Specifically, selective thermal transfer of color filters, black matrix, spacers, polarizers, conductive layers, transistors, phosphors, and organic electroluminescent materials have all been proposed.
The ability to selectively thermally transfer organic electronically active materials can allow a wide variety of organic electronic devices to be made that cannot currently be made by conventional means. For example, while emission of polarized light from oriented organic electroluminescent materials has been demonstrated in the literature, the ability to pattern devices or to make displays utilizing organic polarized light emitting devices has not been shown. The present invention provides methods for patterning oriented electronically active organic materials, and thus for the first time enables the fabrication and manufacture of patterned organic electronic displays and devices. Such devices include organic transistors and other such electronic devices that have oriented conductive or semiconductive polymer layers, for example to enhance charge mobility properties in the device. Other such devices include organic electroluminescent devices and pixilated displays that incorporate oriented organic emissive materials, for example to emit linearly or circularly polarized light.
In one aspect, the present invention provides a process for making an organic electroluminescent device by selectively thermally transferring a transfer layer comprising an oriented organic emissive material from a donor sheet to a receptor substrate that has a first electrode, and forming a second electrode so that the oriented organic emissive material is positioned between the first and second electrodes, wherein the device is capable of emitting polarized light when activated.
In another aspect, the present invention provides a process for making an organic electronic device by selectively thermally transferring a transfer layer comprising an oriented electronically active polymer from a donor sheet to a device substrate, and connecting the oriented electronically active polymer layer on the device substrate to other layers of the organic electronic device to form a completed device.
In yet another aspect, the present invention provides a donor sheet comprising a selectively thermally transferable transfer layer comprising an oriented organic emissive material capable of emitting polarized light when suitably disposed in an organic electroluminescent device.
In still another aspect, the present invention provides a donor sheet that includes a substrate, an alignment layer, a light-to-heat conversion layer disposed between the substrate and the alignment layer for converting incident imaging radiation into heat, and a transfer layer comprising an oriented light emitting polymer coated onto the alignment layer and capable of being selectively thermally transferred from the donor sheet to a proximately located receptor.
In another aspect, the present invention provides a method of making a donor sheet by providing a donor substrate and forming a transfer layer adjacent to the substrate, the transfer layer including an oriented electronically active organic material capable of being selectively thermally transferred from the donor sheet to a proximately located receptor while substantially maintaining the orientation of the oriented electronically active organic material.